[BUGFIX] Remove double quotations in FileList class

On two occasions there are too many double quotes.

Resolves: #83186
Releases: master
Change-Id: I8708bc5ff1d6ac680bccaab14d407f5ab3222698
Reviewed-on: https://review.typo3.org/54899


Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>